Microbiology 330: Food Poisoning, Skin, Nervous System, and Respiratory Diseases

What are the two classes of food poisoning agents?

Those that produce toxins in food and those that grow in the gut producing toxins.

Which food poisoning agents produce toxins in foods?

Staphylococcus and Clostridia.

Which food poisoning agents grow in the gut and produce toxins?

Salmonella, E. coli, Shigella, and others.

What are key features of Staphylococcal food poisoning?

A protein toxin is released into foods that is not heat labile; symptoms appear quickly and are typically self-limiting.

Why is botulism associated with improper canning?

Clostridium botulinum spores survive boiling and germinate in anaerobic conditions inside cans, producing botulinum toxin.

What is the relationship between Salmonella and typhoid fever?

Typhoid fever is caused by S. typhi, a more invasive species of Salmonella, and there are chronic carriers.

What are key features of Salmonellosis?

Onset can be days or weeks after infection; it causes enteritis with bloody diarrhea.

What roles do Clostridium perfringens play?

It is a food poisoning agent and the causative agent of gas gangrene.

Why is Listeria monocytogenes a concern?

It damages the fetus during pregnancy.

What distinguishes enterohemorrhagic E. coli from normal microflora?

It produces verotoxin and has additional adherence and virulence factors acquired through horizontal gene transfer.

What are key features of Cholera?

Caused by Vibrio, characterized by rice water stools and diarrhea, associated with poor hygiene.

How is Helicobacter pylori related to stomach ulcers?

It neutralizes stomach acid with ammonia, inhibits mucus production, and causes tissue damage.

What are the three major classes of viral hepatitis?

Hepatitis A (foods and blood), Hepatitis B (blood and bodily fluids), and Hepatitis C (blood), all causing chronic infections.

What are the protozoan agents Giardia, Cryptosporidium, and Entamoeba histolytica known for?

Giardia and Cryptosporidium cause bloody diarrhea and are widespread; Entamoeba causes amoebic dysentery.

What are key features of Schistosomiasis?

It causes tumor-like growths on the skin and has a complex life cycle involving snails as intermediate hosts.

What is trichinosis?

It forms cysts in muscles and can be transmitted by eating diseased animal flesh.

What is Campylobacter?

A common food poisoning agent.

What is polio?

A virus that mainly causes mild enteric disease but can lead to neurological involvement and paralysis.

What are the features of Streptococcal diseases?

Includes erysipelas (red skin infection), impetigo (blisters), and necrotizing fasciitis (flesh-eating bacteria).

What are the virulence factors of Staphylococcus aureus?

Capsule, antibiotic resistance, and toxins.

What causes acne?

Propionibacterium acnes infects sebaceous glands.

What is gas gangrene?

An anaerobic infection caused by Clostridium perfringens in ischemic tissue.

What distinguishes measles from rubella?

Measles is highly contagious with high mortality; rubella is mild except during pregnancy.

What is the life cycle of chicken pox and its relationship to shingles?

Chicken pox can lie latent in spinal ganglia and reactivate as shingles.

What are the classes of mycoses?

Cutaneous (surface), subcutaneous (deeper dermal layers), and systemic (disseminated throughout the body).

What are tineas?

Ringworm infections, including athlete's foot, scalp, and body infections.

What is candidiasis?

Disease caused by Candida albicans, common in diaper rash and can cause thrush.

What diseases are associated with vectors?

West Nile virus, arboviruses, malaria (mosquitoes); Lyme disease, RMSF (ticks); typhus, plague (rats).

What are key features of toxoplasmosis?

Carried by cats, mild disease, but can have severe outcomes in pregnancy.

What is the nature of trypanosomiasis?

Chronic undulating disease with fever, including African sleeping sickness and Chagas disease.

What are the classes of typhus?

Louse borne (epidemic), tick borne, mouse borne (endemic).

What is the etiology of Lyme disease?

Carried by deer ticks, characterized by a bulls-eye rash and potential arthritis and dementia.

What is the general life cycle of malaria?

Caused by Plasmodium; involves merozoites in mosquitoes, sporozoites injected into hosts, and lifecycle stages in red blood cells.

What is the life cycle of the retrovirus HIV?

HIV integrates into helper T-cells, leading to AIDS after a latent period and opportunistic infections.

What is the life cycle of the latent virus Herpes?

Infects skin through contact, forms blisters, and migrates to spinal ganglia.

What are herpetic lesions?

Blisters that break open and scab, caused by the herpes virus.

What is the difference between HSV-1 and HSV-2?

HSV-1 is associated with oral fever blisters; HSV-2 is associated with genital herpes and is more virulent.

What are the three progressive stages of syphilis?

Primary syphilis: genital sore; Secondary syphilis: rash and symptoms weeks later; Tertiary syphilis: dementia and gummas.

What is Trachoma?

A chlamydial disease that causes scarring of the cornea and is the leading cause of preventable blindness.

What are the key features of Gonorrhea?

Caused by Neisseria gonorrhoeae, it leads to purulent infection of the urethra.

What causes vaginitis?

Often caused by an upset of normal vaginal microflora, with Candida albicans being a common cause.

What is cystitis?

Inflammation of the urinary bladder.

What is urethritis?

Inflammation of the urethra.

What is pyelonephritis?

A dangerous kidney infection.

What are the major causative agents of UTIs?

Typically enteric bacteria like E. coli and specialized pathogens like Ureaplasma.

What is rheumatic fever?

A disease caused by Streptococcus leading to joint inflammation and heart valve damage.

What are the three classes of bacterial meningitis?

Hemophilus influenzae, Streptococcus pneumoniae, and Neisseria meningitidis.

What is arboviral encephalitis?

Swelling of the brain caused by viruses transmitted by mosquitoes.

What is a prion?

Proteinaceous infectious particles that cause disease by misfolding normal brain proteins.

What are the major prion diseases?

Mad Cow disease, Scrapie, and Kuru.

What is rabies?

A viral disease spread through animal bites, leading to neurological issues.

What causes tetanus?

Clostridium tetani, which produces a toxin affecting muscle relaxation.

What are the types of leprosy?

Tuberculoid leprosy (mild) and lepromatous leprosy (progressive with nerve damage).

What are the three types of plague?

Bubonic (lymphatic), Pneumonic (lungs), and Septicemic (blood).

What is the structure of the influenza virus?

It has a protein capsid with 8 RNA segments, a lipid envelope, and spike proteins.

What is antigenic drift?

Small changes in influenza virus surface antigens due to mutations.

What is antigenic shift?

Large changes in influenza virus surface antigens due to mixing of RNA segments.

What are the types of influenza?

Type A (epidemics and pandemics), Type B (epidemics), Type C (less common).

What is histoplasmosis?

A systemic mycosis known as Ohio Valley Fever, causing flu-like symptoms and lung calcifications.

What is the pathology of tuberculosis?

Mycobacterium tuberculosis survives in macrophages, leading to granuloma formation and potential lung infection.

What are the types of bacterial pneumonias?

Hemophilus influenzae, Streptococcus pneumoniae, Mycoplasma pneumoniae, and Klebsiella pneumoniae.

What are the key features of pertussis?

Caused by Bordetella, leading to a paralyzed ciliary escalator and three stages: proximal, catarrhal, and convalescent.

What is diphtheria?

A disease that forms a pseudomembrane at the back of the throat.

What is pneumocystis?

A minor form of pneumonia.